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van den Dobbelsteen M, Hackett SL, van Asselen B, Oolbekkink S, Wolthaus JW, de Vries JW, Raaymakers BW. Experimental validation of multi-fraction online adaptations in magnetic resonance guided radiotherapy. Phys Imaging Radiat Oncol 2023; 28:100507. [PMID: 38035206 PMCID: PMC10685304 DOI: 10.1016/j.phro.2023.100507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
Background and purpose Radiotherapy plan verification is generally performed on the reference plan based on the pre-treatment anatomy. However, the introduction of online adaptive treatments demands a new approach, as plans are created daily on different anatomies. The aim of this study was to experimentally validate the accuracy of total doses of multi-fraction plan adaptations in magnetic resonance imaging guided radiotherapy in a phantom study, isolated from the uncertainty of deformable image registration. Materials and methods We experimentally verified the total dose, measured on external beam therapy 3 (EBT3) film, using a treatment with five online adapted fractions. Three series of experiments were performed, each focusing on a category of inter-fractional variation; translations, rotations and body modifications. Variations were introduced during each fraction and adapted plans were generated and irradiated. Single fraction doses and total doses over five online adapted fractions were investigated. Results The online adapted measurements and calculations showed a good agreement for single fractions and multi-fraction treatments for the dose profiles, gamma passing rates, dose deviations and distances to agreement. The gamma passing rate using a 2%/2 mm criterion ranged from 99.2% to 99.5% for a threshold dose of 10% of the maximum dose (Dmax) and from 96.2% to 100% for a threshold dose of 90% of Dmax, for the total translations, rotations and body modifications. Conclusions The total doses of multi-fraction treatments showed similar accuracies compared to single fraction treatments, indicating an accurate dosimetric outcome of a multi-fraction treatment in adaptive magnetic resonance imaging guided radiotherapy.
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Affiliation(s)
- Madelon van den Dobbelsteen
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Sara L. Hackett
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Bram van Asselen
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Stijn Oolbekkink
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Jochem W.H. Wolthaus
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - J.H. Wilfred de Vries
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Bas W. Raaymakers
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Patrick HM, Poon E, Kildea J. Experimental validation of a novel method of dose accumulation for the rectum. Acta Oncol 2023; 62:915-922. [PMID: 37504890 DOI: 10.1080/0284186x.2023.2238556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/08/2023] [Indexed: 07/29/2023]
Abstract
BACKGROUND Dose-surface maps (DSMs) are an increasingly popular tool to evaluate spatial dose-outcome relationships for the rectum. Recently, DSM addition has been proposed as an alternative method of dose accumulation from deformable registration-based techniques. In this study, we performed the first experimental investigation of the accuracy at which DSM accumulation can capture the total dose delivered to a rectum's surface in the presence of inter-fraction motion. MATERIAL AND METHODS A custom PVC rectum phantom capable of representing typical rectum inter-fraction motion and filling variations was constructed for this project. The phantom allowed for the placement of EBT3 film sheets on the representative rectum surface to measure rectum surface dose. A multi-fraction prostate VMAT treatment was designed and delivered to the phantom in a water tank for a variety of inter-fraction motion scenarios. DSMs for each fraction were calculated in two ways using CBCT images acquired during delivery and summed to produce accumulated DSMs. Accumulated DSMs were then compared to film measurements using gamma analysis (3%/2 mm criteria). Similarity of isodose clusters between films and DSMs was also investigated. RESULTS Baseline agreement between film measurements and accumulated DSMs for a stationary rectum was 95.6%. Agreement between film and accumulated DSMs in the presence of different types of inter.-fraction motion was ≥92%, and isodose cluster mean distance to agreement was within 1.5 mm for most scenarios. Overall, DSM accumulation performed the best when using DSMs that accounted for changes in rectum path orientation. CONCLUSION Dose accumulation performed with DSMs was found to accurately replicate total delivered dose to a rectum phantom in the presence of inter-fraction motion.
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Affiliation(s)
- H M Patrick
- Medical Physics Unit, McGill University, Montreal, Québec, Canada
| | - E Poon
- Department of Medical Physics, McGill University Health Centre, Montreal, Québec, Canada
| | - J Kildea
- Medical Physics Unit, McGill University, Montreal, Québec, Canada
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
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3
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Bessieres I, Lorenzo O, Bertaut A, Petitfils A, Aubignac L, Boudet J. Online adaptive radiotherapy and dose delivery accuracy: A retrospective analysis. J Appl Clin Med Phys 2023:e14005. [PMID: 37097765 PMCID: PMC10402677 DOI: 10.1002/acm2.14005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/16/2023] [Accepted: 04/04/2023] [Indexed: 04/26/2023] Open
Abstract
PURPOSE With online adaptive radiotherapy (ART), patient-specific quality assurance (PSQA) testing cannot be performed prior to delivery of the adapted treatment plan. Consequently, the dose delivery accuracy of adapted plans (i.e., the ability of the system to interpret and deliver the treatment as planned) are not initially verified. We investigated the variation in dose delivery accuracy of ART on the MRIdian 0.35 T MR-linac (Viewray Inc., Oakwood, USA) between initial plans and their respective adapted plans, by analyzing PSQA results. METHODS We considered the two main digestive localizations treated with ART (liver and pancreas). A total of 124 PSQA results acquired with the ArcCHECK (Sun Nuclear Corporation, Melbourne, USA) multidetector system were analyzed. PSQA result variations between the initial plans and their respective adapted plans were statistically investigated and compared with the variation in MU number. RESULTS For the liver, limited deterioration in PSQA results was observed, and was within the limits of clinical tolerance (Initial = 98.2%, Adapted = 98.2%, p = 0.4503). For pancreas plans, only a few significant deteriorations extending beyond the limits of clinical tolerance were observed and were due to specific, complex anatomical configurations (Initial = 97.3%, Adapted = 96.5%, p = 0.0721). In parallel, we observed an influence of the increase in MU number on the PSQA results. CONCLUSION We show that the dose delivery accuracy of adapted plans, in terms of PSQA results, is preserved in ART processes on the 0.35 T MR-linac. Respecting good practices, and minimizing the increase in MU number can help to preserve the accuracy of delivery of adapted plans as compared to their respective initial plans.
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Affiliation(s)
- Igor Bessieres
- Department of Medical Physics, Centre Georges François Leclerc, Dijon, France
| | - Olivier Lorenzo
- Department of Medical Physics, Centre Georges François Leclerc, Dijon, France
| | - Aurélie Bertaut
- Methodology, Data-Management and Biostatistics Unit, Centre Georges-François Leclerc, Dijon, France
| | - Aurélie Petitfils
- Department of Medical Physics, Centre Georges François Leclerc, Dijon, France
| | - Léone Aubignac
- Department of Medical Physics, Centre Georges François Leclerc, Dijon, France
| | - Julien Boudet
- Department of Medical Physics, Centre Georges François Leclerc, Dijon, France
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4
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Shariff M, Grigo J, Masitho S, Brandt T, Weiss A, Lambrecht U, Stillkrieg W, Lotter M, Putz F, Fietkau R, Bert C. End-to-end testing for stereotactic radiotherapy including the development of a Multi-Modality phantom. Z Med Phys 2022:S0939-3889(22)00123-4. [PMID: 36539322 DOI: 10.1016/j.zemedi.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE A new insert for a commercially available end-to-end test phantom was designed and in-house manufactured by 3D printing. Subsequently, the insert was tested for different stereotactic radiation therapy workflows (SRS, SBRT, FSRT, and Multimet) also in comparison to the original insert. MATERIAL AND METHODS Workflows contained imaging (MR, CT), treatment planning, positioning, and irradiation. Positioning accuracy was evaluated for non-coplanar x-ray, kV- and MV-CBCT systems, as well as surface guided radiation therapy. Dosimetric accuracy of the irradiation was measured with an ionization chamber at four different linear accelerators including dynamic tumor tracking for SBRT. RESULTS CT parameters of the insert were within the specification. For MR images, the new insert allowed quantitative analysis of the MR distortion. Positioning accuracy of the phantom with the new insert using the imaging systems of the different linacs was < 1 mm/degree also for MV-CBCT and a non-coplanar imaging system which caused > 3 mm deviation with the original insert. Deviation of point dose values was <3% for SRS, FSRT, and SBRT for both inserts. For the Multimet plans deviations exceeded 10% because the ionization chamber was not positioned in each metastasis, but in the center of phantom and treatment plan. CONCLUSION The in-house manufactured insert performed well in all steps of four stereotactic treatment end-to-end tests. Advantages over the commercially available alternative were seen for quantitative analysis of deformation correction in MR images, applicability for non-coplanar x-ray imaging, and dynamic tumor tracking.
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Affiliation(s)
- Maya Shariff
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| | - Johanna Grigo
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Siti Masitho
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Tobias Brandt
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Alexander Weiss
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Ulrike Lambrecht
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Willi Stillkrieg
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Michael Lotter
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Florian Putz
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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5
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Nierer L, Kamp F, Reiner M, Corradini S, Rabe M, Dietrich O, Parodi K, Belka C, Kurz C, Landry G. Evaluation of an anthropomorphic ion chamber and 3D gel dosimetry head phantom at a 0.35 T MR-linac using separate 1.5 T MR-scanners for gel readout. Z Med Phys 2022; 32:312-325. [PMID: 35305857 PMCID: PMC9948847 DOI: 10.1016/j.zemedi.2022.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/27/2022] [Accepted: 01/31/2022] [Indexed: 12/22/2022]
Abstract
PURPOSE To date, no universally accepted technique for the evaluation of the overall dosimetric performance of hybrid integrated magnetic resonance imaging (MR) - linear accelerators (linacs) is available. We report on the suitability and reliability of a novel phantom with modular inserts for combined polymer gel (PG) and ionisation chamber (IC) measurements at a 0.35 T MR-linac. METHODS Three 3D-printed, modular head phantoms, based on real patient anatomy, were used for repeated (2 times) PG irradiations of cranial treatment plans on a 0.35 T MR-linac. The PG readout was performed on two 1.5 T diagnostic MR-scanners to reduce scanning time. The PG dose volumes were normalised to the IC dose (normalised dose N1) and to the median planning target volume dose (normalised dose N2). Linearity of the PG dose response was validated and dose profiles, centres of mass (COM) of the 95% isodoses and dose volume histograms (DVH) were compared between planned and measured dose distributions and a 3D gamma analysis was performed. RESULTS Dose linearity of the PG was good (R2> 0.99 for all linear fit functions). High agreement was found between planned and measured dose volumes in the dose profiles and DVHs. The largest dose deviation was found in the intermediate dose region (mean dose deviation 0.2Gy; 5.6%). A mean COM offset of 1.2mm indicated high spatial accuracy. Mean 3D gamma passing rates (2%, 2mm) of 83.3% for N1 and 91.6% for N2 dose distributions were determined. When comparing repeated PG measurements to each other, a mean gamma passing rate of 95.7% was found. CONCLUSION The new modular phantom was found practical for use at a 0.35 T MR-linac. In contrast to the high dose region, larger mean deviations were found in the mid dose range. The PG measurements showed high reproducibility. The MR-linac performed well in a non-adaptive setting in terms of spatial and dosimetric accuracy.
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Affiliation(s)
- Lukas Nierer
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany.
| | - Florian Kamp
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany; Department of Radiation Oncology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany
| | - Michael Reiner
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Moritz Rabe
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Olaf Dietrich
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Katia Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Claus Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany; German Cancer Consortium (DKTK), partner site Munich, Munich, Germany
| | - Christopher Kurz
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Guillaume Landry
- Department of Radiation Oncology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
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6
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Rippke C, Schrenk O, Renkamp CK, Buchele C, Hörner-Rieber J, Debus J, Alber M, Klüter S. Quality assurance for on-table adaptive magnetic resonance guided radiation therapy: A software tool to complement secondary dose calculation and failure modes discovered in clinical routine. J Appl Clin Med Phys 2022; 23:e13523. [PMID: 35019212 PMCID: PMC8906229 DOI: 10.1002/acm2.13523] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/14/2021] [Accepted: 12/19/2021] [Indexed: 11/16/2022] Open
Abstract
Online adaption of treatment plans on a magnetic resonance (MR)‐Linac enables the daily creation of new (adapted) treatment plans using current anatomical information of the patient as seen on MR images. Plan quality assurance (QA) relies on a secondary dose calculation (SDC) that is required because a pretreatment measurement is impossible during the adaptive workflow. However, failure mode and effect analysis of the adaptive planning process shows a large number of error sources, and not all of them are covered by SDC. As the complex multidisciplinary adaption process takes place under time pressure, additional software solutions for pretreatment per‐fraction QA need to be used. It is essential to double‐check SDC input to ensure a safe treatment delivery. Here, we present an automated treatment plan check tool for adaptive radiotherapy (APART) at a 0.35 T MR‐Linac. It is designed to complement the manufacturer‐provided adaptive QA tool comprising SDC. Checks performed by APART include contour analysis, electron density map examinations, and fluence modulation complexity controls. For nine of 362 adapted fractions (2.5%), irregularities regarding missing slices in target volumes and organs at risks as well as in margin expansion of target volumes have been found. This demonstrates that mistakes occur and can be detected by additional QA measures, especially contour analysis. Therefore, it is recommended to implement further QA tools additional to what the manufacturer provides to facilitate an informed decision about the quality of the treatment plan.
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Affiliation(s)
- Carolin Rippke
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany.,Medical Faculty, University of Heidelberg, Heidelberg, Baden-Wurttemberg, Germany
| | - Oliver Schrenk
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany.,PTW-Freiburg, Freiburg, Baden-Wurttemberg, Germany
| | - C Katharina Renkamp
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany
| | - Carolin Buchele
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany
| | - Juliane Hörner-Rieber
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany.,Medical Faculty, University of Heidelberg, Heidelberg, Baden-Wurttemberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg, Baden-Wurttemberg, Germany.,German Cancer Consortium (DKTK), Core-center Heidelberg, Heidelberg, Baden-Wurttemberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Baden-Wurttemberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany.,Medical Faculty, University of Heidelberg, Heidelberg, Baden-Wurttemberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Baden-Wurttemberg, Germany.,German Cancer Consortium (DKTK), Core-center Heidelberg, Heidelberg, Baden-Wurttemberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Baden-Wurttemberg, Germany
| | - Markus Alber
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany.,Medical Faculty, University of Heidelberg, Heidelberg, Baden-Wurttemberg, Germany
| | - Sebastian Klüter
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Baden-Wurttemberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg, Baden-Wurttemberg, Germany
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7
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Elter A, Rippke C, Johnen W, Mann P, Hellwich E, Schwahofer A, Dorsch S, Buchele C, Klüter S, Karger CP. End-to-end test for fractionated online adaptive MR-guided radiotherapy using a deformable anthropomorphic pelvis phantom. Phys Med Biol 2021; 66. [PMID: 34845991 DOI: 10.1088/1361-6560/ac3e0c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/29/2021] [Indexed: 11/12/2022]
Abstract
Objective.In MR-guided radiotherapy (MRgRT) for prostate cancer treatments inter-fractional anatomy changes such as bladder and rectum fillings may be corrected by an online adaption of the treatment plan. To clinically implement such complex treatment procedures, however, specific end-to-end tests are required that are able to validate the overall accuracy of all treatment steps from pre-treatment imaging to dose delivery.Approach.In this study, an end-to-end test of a fractionated and online adapted MRgRT prostate irradiation was performed using the so-called ADAM-PETer phantom. The phantom was adapted to perform 3D polymer gel (PG) dosimetry in the prostate and rectum. Furthermore, thermoluminescence detectors (TLDs) were placed at the center and on the surface of the prostate for additional dose measurements as well as for an external dose renormalization of the PG. For the end-to-end test, a total of five online adapted irradiations were applied in sequence with different bladder and rectum fillings, respectively.Main results.A good agreement of measured and planned dose was found represented by highγ-index passing rates (3%/3mmcriterion) of the PG evaluation of98.9%in the prostate and93.7%in the rectum. TLDs used for PG renormalization at the center of the prostate showed a deviation of-2.3%.Significance.The presented end-to-end test, which allows for 3D dose verification in the prostate and rectum, demonstrates the feasibility and accuracy of fractionated and online-adapted prostate irradiations in presence of inter-fractional anatomy changes. Such tests are of high clinical importance for the commissioning of new image-guided treatment procedures such as online adaptive MRgRT.
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Affiliation(s)
- A Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - C Rippke
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany.,Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - W Johnen
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - P Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - E Hellwich
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - A Schwahofer
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - S Dorsch
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - C Buchele
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany.,Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - S Klüter
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
| | - C P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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8
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Nenoff L, Matter M, Charmillot M, Krier S, Uher K, Weber DC, Lomax AJ, Albertini F. Experimental validation of daily adaptive proton therapy. Phys Med Biol 2021; 66. [PMID: 34587589 DOI: 10.1088/1361-6560/ac2b84] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 09/29/2021] [Indexed: 11/12/2022]
Abstract
Anatomical changes during proton therapy require rapid treatment plan adaption to mitigate the associated dosimetric impact. This in turn requires a highly efficient workflow that minimizes the time between imaging and delivery. At the Paul Scherrer Institute, we have developed an online adaptive workflow, which is specifically designed for treatments in the skull-base/cranium, with the focus set on simplicity and minimizing changes to the conventional workflow. The dosimetric and timing performance of this daily adaptive proton therapy (DAPT) workflow has been experimentally investigated using an in-house developed DAPT software and specifically developed anthropomorphic phantom. After a standard treatment preparation, which includes the generation of a template plan, the treatment can then be adapted each day, based on daily imaging acquired on an in-room CT. The template structures are then rigidly propagated to this CT and the daily plan is fully re-optimized using the same field arrangement, DVH constraints and optimization settings of the template plan. After a dedicated plan QA, the daily plan is delivered. To minimize the time between imaging and delivery, clinically integrated software for efficient execution of all online adaption steps, as well as tools for comprehensive and automated QA checks, have been developed. Film measurements of an end-to-end validation of a multi-fraction DAPT treatment showed high agreement to the calculated doses. Gamma pass rates with a 3%/3 mm criteria were >92% when comparing the measured dose to the template plan. Additionally, a gamma pass rate >99% was found comparing measurements to the Monte Carlo dose of the daily plans reconstructed from the logfile, accumulated over the delivered fractions. With this, we experimentally demonstrate that the described adaptive workflow can be delivered accurately in a timescale similar to a standard delivery.
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Affiliation(s)
- Lena Nenoff
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland.,Department of Physics, ETH Zurich, Switzerland
| | - Michael Matter
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland.,Department of Physics, ETH Zurich, Switzerland
| | | | - Serge Krier
- Department of Physics, ETH Zurich, Switzerland
| | - Klara Uher
- Department of Physics, ETH Zurich, Switzerland
| | - Damien Charles Weber
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland.,Department of Radiation Oncology, University Hospital Zurich, Switzerland.,Department of Radiation Oncology, University Hospital Bern, Switzerland
| | - Antony John Lomax
- Paul Scherrer Institute, Center for Proton Therapy, Switzerland.,Department of Physics, ETH Zurich, Switzerland
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9
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Iijima K, Okamoto H, Nishioka S, Sakasai T, Nakamura S, Chiba T, Kaga K, Takemori M, Nakayama H, Miura Y, Fujiyama D, Tsunoda Y, Igaki H, Katsuta S, Itami J. Performance of a newly designed end-to-end phantom compatible with magnetic resonance-guided radiotherapy systems. Med Phys 2021; 48:7541-7551. [PMID: 34510486 DOI: 10.1002/mp.15153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE In this study, we report on our proposed phantom based on the new end-to-end (E2E) methodology and its results. In addition, we verify whether the proposed phantom can replace conventional phantoms. METHODS The hexagonal-shaped newly designed phantom has pockets on each side for a film dosimeter of size 80 × 90 mm2 , which is easily removable, considering the 60 Co penumbra. The new phantom comprises water, shell, and auxiliary shell phantoms. The shell and auxiliary shell materials are Solid Water HE. A mock tumor (aluminum oxide) was attached by a single prop in the water phantom and placed at the center of the new phantom. The results of a conventional E2E test were compared with those of the novel E2E test using the newly designed phantom. The irradiated film dosimeter in the novel E2E test was scanned in a flatbed scanner and analyzed using an in-house software developed with MATLAB. The irradiated field center, laser center, and mock tumor center were calculated. In the novel image-matching E2E (IM-E2E) test, image matching is performed by aligning the laser center with ruled lines. In the novel irradiation-field E2E (IF-E2E) test, the displacement of the irradiation-field center was defined as its distance from the laser center. In the composite E2E test, the overall displacement, which included the accuracy of the irradiated field and image matching, was defined as the distance between the irradiated field center and mock tumor center. In addition, using the newly designed phantom, the overall irradiation accuracy of the machine was evaluated by calculating the three-dimensional (3D) center of the irradiated field, phantom, and laser. The composite E2E test could be performed using the newly designed phantom only. RESULTS In the IM-E2E test, the results of the conventional and novel IM-E2E tests were significantly different in each direction (left-right direction: p-value < < 0.05, anterior-posterior direction: p-value = 0.002, and superior-inferior direction: p-value = 0.002). The displacement directions were the same in both the conventional and novel IM-E2E tests. In the analysis of the IF-E2E test, no significant difference was evident between the results in each direction. Moreover, the displacement directions were the same in the conventional and novel IF-E2E tests, except for the left-right lateral direction of head three. In addition, the 3D analysis results of the novel IF-E2E test were less than 1 mm in all directions. In the analysis of the composite E2E test, the maximum displacement was 1.4 mm in all directions. In addition, almost all results of 3D analysis for the composite E2E test were less than 1 mm in all directions. CONCLUSION The newly designed E2E phantom simplifies the E2E test for MRIdian, and is a possible alternative to the conventional E2E test. Furthermore, we can perform the previously unfeasible composite E2E tests that include the entire treatment process.
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Affiliation(s)
- Kotaro Iijima
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan
| | - Hiroyuki Okamoto
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan
| | - Shie Nishioka
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan
| | - Tatsuya Sakasai
- Department of Radiological Technology Radiological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Satoshi Nakamura
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan
| | - Takahito Chiba
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan.,Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Keita Kaga
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan.,Department of Radiological Technology Radiological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Mihiro Takemori
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan.,Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Hiroki Nakayama
- Department of Medical Physics, National Cancer Center Hospital, Tokyo, Japan.,Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Yuki Miura
- Department of Radiological Technology Radiological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Daisuke Fujiyama
- Department of Radiological Technology Radiological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Yuki Tsunoda
- Department of Radiological Technology Radiological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Hiroshi Igaki
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Shoichi Katsuta
- Department of Radiological Technology Radiological Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Jun Itami
- Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
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10
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Marot M, Elter A, Mann P, Schwahofer A, Lang C, Johnen W, Körber SA, Beuthien-Baumann B, Gillmann C. Technical Note: On the feasibility of performing dosimetry in target and organ at risk using polymer dosimetry gel and thermoluminescence detectors in an anthropomorphic, deformable, and multimodal pelvis phantom. Med Phys 2021; 48:5501-5510. [PMID: 34260079 DOI: 10.1002/mp.15096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/28/2021] [Accepted: 06/25/2021] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE To assess the feasibility of performing dose measurements in the target (prostate) and an adjacent organ at risk (rectum) using polymer dosimetry gel and thermoluminescence detectors (TLDs) in an anthropomorphic, deformable, and multimodal pelvis phantom (ADAM PETer). METHODS The 3D printed prostate organ surrogate of the ADAM PETer phantom was filled with polymer dosimetry gel. Nine TLD600 (LiF:Mg,Ti) were installed in 3 × 3 rows on a specifically designed 3D-printed TLD holder. The TLD holder was inserted into the rectum at the level of the prostate and fixed by a partially inflated endorectal balloon. Computed tomography (CT) images were taken and treatment planning was performed. A prescribed dose of 4.5 Gy was delivered to the planning target volume (PTV). The doses measured by the dosimetry gel in the prostate and the TLDs in the rectum ("measured dose") were compared to the doses calculated by the treatment planning system ("planned dose") on a voxel-by-voxel basis. RESULTS In the prostate organ surrogate, the 3D-γ-index was 97.7% for the 3% dose difference and 3 mm distance to agreement criterium. In the center of the prostate organ surrogate, measured and planned doses showed only minor deviations (<0.1 Gy, corresponding to a percentage error of 2.22%). On the edges of the prostate, slight differences between planned and measured doses were detected with a maximum deviation of 0.24 Gy, corresponding to 5.3% of the prescribed dose. The difference between planned and measured doses in the TLDs was on average 0.08 Gy (range: 0.02-0.21 Gy), corresponding to 1.78% of the prescribed dose (range: 0.44%-4.67%). CONCLUSIONS The present study demonstrates the feasibility of using polymer dosimetry gel and TLDs for 3D and 1D dose measurements in the prostate and the rectum organ surrogates in an anthropomorphic, deformable and multimodal phantom. The described methodology might offer new perspectives for end-to-end tests in image-guided adaptive radiotherapy workflows.
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Affiliation(s)
- Mathieu Marot
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Medicine, University of Heidelberg, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Alina Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Philipp Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,HQ-Imaging GmbH, Heidelberg, Germany
| | - Andrea Schwahofer
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Clemens Lang
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Wibke Johnen
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Stefan A Körber
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Bettina Beuthien-Baumann
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Clarissa Gillmann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg, Germany
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11
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Roberts DA, Sandin C, Vesanen PT, Lee H, Hanson IM, Nill S, Perik T, Lim SB, Vedam S, Yang J, Woodings SW, Wolthaus JWH, Keller B, Budgell G, Chen X, Li XA. Machine QA for the Elekta Unity system: A Report from the Elekta MR-linac consortium. Med Phys 2021; 48:e67-e85. [PMID: 33577091 PMCID: PMC8251771 DOI: 10.1002/mp.14764] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 01/21/2021] [Accepted: 02/03/2021] [Indexed: 12/31/2022] Open
Abstract
Over the last few years, magnetic resonance image‐guided radiotherapy systems have been introduced into the clinic, allowing for daily online plan adaption. While quality assurance (QA) is similar to conventional radiotherapy systems, there is a need to introduce or modify measurement techniques. As yet, there is no consensus guidance on the QA equipment and test requirements for such systems. Therefore, this report provides an overview of QA equipment and techniques for mechanical, dosimetric, and imaging performance of such systems and recommendation of the QA procedures, particularly for a 1.5T MR‐linac device. An overview of the system design and considerations for QA measurements, particularly the effect of the machine geometry and magnetic field on the radiation beam measurements is given. The effect of the magnetic field on measurement equipment and methods is reviewed to provide a foundation for interpreting measurement results and devising appropriate methods. And lastly, a consensus overview of recommended QA, appropriate methods, and tolerances is provided based on conventional QA protocols. The aim of this consensus work was to provide a foundation for QA protocols, comparative studies of system performance, and for future development of QA protocols and measurement methods.
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Affiliation(s)
- David A Roberts
- Elekta Limited, Cornerstone, London Road, Crawley, RH10 9BL, United Kingdom
| | - Carlos Sandin
- Elekta Limited, Cornerstone, London Road, Crawley, RH10 9BL, United Kingdom
| | | | - Hannah Lee
- Allegheny Health Network Cancer Institute, Pennsylvania, USA
| | - Ian M Hanson
- The Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, UK
| | - Simeon Nill
- The Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, UK
| | - Thijs Perik
- Department of Radiation Oncology, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands
| | - Seng Boh Lim
- Memorial Sloan Kettering Cancer Center, New York, USA
| | - Sastry Vedam
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Texas, USA
| | - Jinzhong Yang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Texas, USA
| | - Simon W Woodings
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Jochem W H Wolthaus
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Brian Keller
- Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Geoff Budgell
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Wilmslow Road, Manchester, United Kingdom
| | - Xinfeng Chen
- Department of Radiation Oncology, Froedtert Hospital and Medical College of Wisconsin, Milwaukee, USA
| | - X Allen Li
- Department of Radiation Oncology, Froedtert Hospital and Medical College of Wisconsin, Milwaukee, USA
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12
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Axford A, Dikaios N, Roberts DA, Clark CH, Evans PM. An end-to-end assessment on the accuracy of adaptive radiotherapy in an MR-linac. Phys Med Biol 2021; 66:055021. [PMID: 33503604 DOI: 10.1088/1361-6560/abe053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To develop and demonstrate an end-to-end assessment procedure for adaptive radiotherapy (ART) within an MR-guided system. METHODS AND MATERIALS A 3D printed pelvic phantom was designed and constructed for use in this study. The phantom was put through the complete radiotherapy treatment chain, with planned internal changes made to model prostate translations and shape changes, allowing an investigation into three ART techniques commonly used. Absolute dosimetry measurements were made within the phantom using both gafchromic film and alanine. Comparisons between treatment planning system (TPS) calculations and measured dose values were made using the gamma evaluation with criteria of 3 mm/3% and 2 mm/2%. RESULTS Gamma analysis evaluations for each type of treatment plan adaptation investigated showed a very high agreement with pass rates for each experiment ranging from 98.10% to 99.70% and 92.60% to 97.55%, for criteria of 3%/3 mm and 2%/2 mm respectively. These pass rates were consistent for both shape and position changes. Alanine measurements further supported the results, showing an average difference of 1.98% from the TPS. CONCLUSION The end-to-end assessment procedure provided demanding challenges for treatment plan adaptations to demonstrate the capabilities and achieved high consistency in all findings.
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Affiliation(s)
- A Axford
- The Centre for Vision Speech and Signal Processing (CVSSP), University of Surrey, Guildford, Surrey, United Kingdom. Metrology for Medical Physics (MEMPHYS), National Physical Laboratory, Teddington, United Kingdom
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13
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Gillmann C, Homolka N, Johnen W, Runz A, Echner G, Pfaffenberger A, Mann P, Schneider V, Hoffmann AL, Troost EGC, Koerber SA, Kotzerke J, Beuthien-Baumann B. Technical Note: ADAM PETer - An anthropomorphic, deformable and multimodality pelvis phantom with positron emission tomography extension for radiotherapy. Med Phys 2020; 48:1624-1632. [PMID: 33207020 DOI: 10.1002/mp.14597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/10/2020] [Accepted: 10/29/2020] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE To develop an anthropomorphic, deformable and multimodal pelvis phantom with positron emission tomography extension for radiotherapy (ADAM PETer). METHODS The design of ADAM PETer was based on our previous pelvis phantom (ADAM) and extended for compatibility with PET and use in 3T magnetic resonance imaging (MRI). The formerly manually manufactured silicon organ surrogates were replaced by three-dimensional (3D) printed organ shells. Two intraprostatic lesions, four iliac lymph node metastases and two pelvic bone metastases were added to simulate prostate cancer as multifocal and metastatic disease. Radiological properties [computed tomography (CT) and 3T MRI] of cortical bone, bone marrow and adipose tissue were simulated by heavy gypsum, a mixture of Vaseline and K2 HPO4 and peanut oil, respectively. For soft tissues, agarose gels with varying concentrations of agarose, gadolinium (Gd) and sodium fluoride (NaF) were developed. The agarose gels were doped with patient-specific activity concentrations of a Fluorine-18 labelled compound and then filled into the 3D printed organ shells of prostate lesions, lymph node and bone metastases. The phantom was imaged at a dual energy CT and a 3T PET/MRI scanner. RESULTS The compositions of the soft tissue surrogates are the following (given as mass fractions of agarose[w%]/NaF[w%]/Gd[w%]): Muscle (4/1/0.027), prostate (1.35/4.2/0.011), prostate lesions (2.25/4.2/0.0085), lymph node and bone metastases (1.4/4.2/0.025). In all imaging modalities, the phantom simulates human contrast. Intraprostatic lesions appear hypointense as compared to the surrounding normal prostate tissue in T2-weighted MRI. The PET signal of all tumors can be localized as focal spots at their respective site. Activity concentrations of 12.0 kBq/mL (prostate lesion), 12.4 kBq/mL (lymph nodes) and 39.5 kBq/mL (bone metastases) were measured. CONCLUSION The ADAM PETer pelvis phantom can be used as multimodal, anthropomorphic model for CT, 3T-MRI and PET measurements. It will be central to simulate and optimize the technical workflow for the integration of PET/MRI-based radiation treatment planning of prostate cancer patients.
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Affiliation(s)
- Clarissa Gillmann
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Noa Homolka
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,Faculty for Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Wibke Johnen
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Armin Runz
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Gernot Echner
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Asja Pfaffenberger
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Philipp Mann
- German Cancer Research Center (DKFZ), Department of Medical Physics in Radiation Oncology, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Verena Schneider
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Aswin L Hoffmann
- OncoRay - National Center for Radiation Research in Oncology, University Hospital Carl Gustav Carus Dresden, Dresden, Germany.,Department for Radiotherapy and Radiation Oncology, Faculty of Medicine, University Hospital Carl Gustav Carus Dresden, Dresden, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Esther G C Troost
- OncoRay - National Center for Radiation Research in Oncology, University Hospital Carl Gustav Carus Dresden, Dresden, Germany.,Department for Radiotherapy and Radiation Oncology, Faculty of Medicine, University Hospital Carl Gustav Carus Dresden, Dresden, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Germany
| | - Stefan A Koerber
- Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Partner Site, Heidelberg, Germany.,Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg, Germany
| | - Jörg Kotzerke
- Department for Radiotherapy and Radiation Oncology, Faculty of Medicine, University Hospital Carl Gustav Carus Dresden, Dresden, Germany.,Department for Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Bettina Beuthien-Baumann
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Partner Site, Heidelberg, Germany
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